Heat dissipation module with wind stop function

ABSTRACT

A heat dissipation module includes a centrifugal fan and a heat dissipation fin array. The centrifugal fan includes at least one axial air inlet and a radial air outlet, wherein the radial air outlet is defined between a first sidewall and an opposite second sidewall with a tongue potion. The heat dissipation fin array is located at the radial air outlet of the centrifugal fan. The heat dissipation fin array and the radial air outlet substantially share an equal length L. The heat dissipation fin array has a middle wind stop section which is closer to the second sidewall than the first sidewall. The wind stop section has a length ranging from about 0.1 L to about 0.42 L.

BACKGROUND

1. Field of Invention

The present invention relates to a heat dissipation module. Moreparticularly, the present invention relates to a heat dissipation moduleequipped with a centrifugal fan.

2. Description of Related Art

A heat dissipation module equipped with a centrifugal fan is used inmost notebook computers as their system coolers. The heat dissipationmodule includes a centrifugal fan, a heat pipe and a heat dissipationfin array. An first end of the heat pipe is used to connect with a heatsource, e.g., a CPU, while a second opposite end of the heat pipe isused to connect with the heat dissipation fin array, therebytransferring heat from the heat source to the heat dissipation finarray. The heat dissipation fin array is fastened to an air outlet ofthe centrifugal fan. When an impeller of the centrifugal fan rotates,airflows carry the heat on the heat dissipation fin array out of thenotebook computer.

However, the notebook computers are designed to be thin and compact, thedissipation modules inside them are also designed to be thinner. Whenthe notebook computers are designed to be less than 20 mm in thickness,a gap between the dissipation module and a top cover or between thedissipation module and a bottom cover becomes narrower. Thus, thecentrifugal fan may draw not enough input air from its axial air inletand perform not very well in the heat dissipation efficiency. For theforgoing reasons, there is a need for dealing the heat dissipationefficiency issue due to the thinner notebook computer design.

SUMMARY

It is therefore an objective of the present invention to provide a heatdissipation module with a wind stop function.

In accordance with the foregoing and other objectives of the presentinvention, a heat dissipation module includes a centrifugal fan and aheat dissipation fin array. The centrifugal fan includes at least oneaxial air inlet and a radial air outlet, wherein the radial air outletis defined between a first sidewall and an opposite second sidewall witha tongue potion. The heat dissipation fin array is located at the radialair outlet of the centrifugal fan. The heat dissipation fin array andthe radial air outlet substantially share an equal length L. The heatdissipation fin array has a middle wind stop section which is closer tothe second sidewall than the first sidewall. The wind stop section has alength ranging from about 0.1 L to about 0.42 L.

According to another embodiment disclosed herein, the length of the windstop section is about 0.26 L.

According to another embodiment disclosed herein, the wind stop sectionbegins 0.48 L from the first sidewall and ends 0.74 L from the firstsidewall.

According to another embodiment disclosed herein, a heat pipe which hasa first end connected with the heat dissipation fin array and a secondopposite end connected with a heat source.

According to another embodiment disclosed herein, the wind stop sectionis a wind-stop sponge contained within the heat dissipation fin array.

According to another embodiment disclosed herein, the wind stop sectionis a wind-stop tape disposed at a side of the heat dissipation fin arraywhich faces the radial air outlet.

According to another embodiment disclosed herein, the wind stop sectionis a wind-stop tape disposed at a side of the heat dissipation fin arraywhich faces away from the radial air outlet.

According to another embodiment disclosed herein, the length of the windstop section is about 0.1 L.

According to another embodiment disclosed herein, the wind stop sectionbegins 0.56 L from the first sidewall and ends 0.66 L from the firstsidewall.

According to another embodiment disclosed herein, the length of the windstop section is about 0.42 L.

According to another embodiment disclosed herein, the wind stop sectionbegins 0.4 L from the first sidewall and ends 0.82 L from the firstsidewall.

According to another embodiment disclosed herein, the centrifugal fancomprises an impeller with multiple blades, and each blade has a freeend curved forward in a rotation direction of the impeller.

Thus, the heat dissipation module disclosed herein employs its wind-stopsection on the heat dissipation fin array to deal with the reverse flowissue at the radial air outlet of the centrifugal fan, thereby resolvingthe hot spot issue on the heat dissipation module as well as thetemperature over-spec. on the bottom cover of the notebook computer.

It is to be understood that both the foregoing general description andthe following detailed description are by examples, and are intended toprovide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention. In the drawings,

FIG. 1 illustrates a perspective view of a heat dissipation moduleaccording to a first embodiment of this invention;

FIG. 2 illustrates a top view of the heat dissipation module in FIG. 1with a wind stop section added and a top cover of the centrifugal fanremoved;

FIG. 3 illustrates a top view of a heat dissipation module with a topcover of the centrifugal fan removed according to a second embodiment ofthis invention;

FIG. 4 illustrates a top view of a heat dissipation module with a topcover of the centrifugal fan removed according to a third embodiment ofthis invention;

FIG. 5 illustrates a top view of a heat dissipation module with a topcover of the centrifugal fan removed according to a fourth embodiment ofthis invention; and

FIG. 6 illustrates a top view of a heat dissipation module with a topcover of the centrifugal fan removed according to a fifth embodiment ofthis invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

FIG. 1 illustrates a perspective view of a heat dissipation moduleaccording to a first embodiment of this invention. The heat dissipationmodule 100 illustrated in FIG. 1 is used in most notebook computers astheir system cooler. The heat dissipation module 100 includes acentrifugal fan 102, a heat pipe 110 and a heat dissipation fin array112. The heat dissipation fin array 112 includes multiple dissipationfins which are arranged in parallel with an airflow direction of aradial air outlet 102 a. A first end 110 a of the heat pipe 110 is usedto connect with a heat source, e.g., a CPU, (not illustrated in thedrawings) while a second opposite end 110 b of the heat pipe 110 is usedto connect with the heat dissipation fin array 112, thereby transferringheat from the first end 110 a to the second end 110 b and the heatdissipation fin array 112. The heat dissipation fin array 112 isfastened to a radial air outlet 102 a of the centrifugal fan to 102.When an impeller 108 of the centrifugal fan 102 rotates, airflows aredrawn into the centrifugal fan 102 from an axial air inlet 102 b andoutput from the radial air outlet 102 a. Therefore, the heat upon theheat dissipation fin array 112 is carried out of the notebook computerby the airflows.

When a thickness of a notebook computer is less than 20 mm, i.e. athickness of a present ultrabook computer, a gap between the centrifugalfan 102 and a top cover of a notebook computer or between thecentrifugal fan 102 and a bottom cover of the notebook computer becomesnarrower. The centrifugal fan 102 is equipped an impeller 108 withmultiple blades 108 a, and each blade 108 a has a free end 108 b curvedforward in a rotation direction 120 of the impeller 108 (also referringto FIG. 2). When the notebook computer operates with a high load, e.g.,playing a 3-D game or a 100% run CPU, a hot spot 113 is detected on theheat dissipation fin array 112. This hot spot 113 results in atemperature over-spec. by about 10 degrees on the bottom cover of thenotebook computer.

An extensive search has been conducted and the problem source has beenfound to be a reverse flow 140 at the radial air outlet 102 a of thecentrifugal fan 102. When the gap between the centrifugal fan 102 and atop cover of the notebook computer or between the centrifugal fan 102and a bottom cover of the notebook computer becomes too narrow, thecentrifugal fan 102 draws less airflows from its (upper or lower) axialair inlet 102 b, the reverse flow 140 occurs at the radial air outlet102 a of the centrifugal fan 102. Several solutions below are developedto deal with the reverse flow 140 at the radial air outlet 102 a.

FIG. 2 illustrates a top view of the heat dissipation module in FIG. 1with a wind stop section added and a top cover of the centrifugal fanremoved. The centrifugal fan 102 is equipped an impeller 108 withmultiple blades 108 a, and each blade 108 a has a free end 108 b curvedforward in a rotation direction 120 of the impeller 108. In order toprevent the reverse flow issue at the radial air outlet 102 a, which isdefined between a first sidewall 102 c and an opposite second sidewall102 b with a tongue potion 102 d, a wind stop section 112 a is designedwithin the heat dissipation fin array 112. In order to specificallydefine the wind stop section 112 a, the length L of the radial airoutlet 102 a is used. In this embodiment, the heat dissipation fin array112 and the radial air outlet 102 a substantially share the equal lengthL. The wind stop section 112 a is middle within the heat dissipation finarray 112 and is closer to the second sidewall 102 b than the firstsidewall 102 c. In this embodiment, the wind stop section 112 a is awind-stop sponge or other wind-stop materials contained within the heatdissipation fin array 112. The wind stop section 112 a is about 0.26 Lin length, which begins 0.48 L from the first sidewall 102 c and ends0.74 L from the first sidewall 102 c.

FIG. 3 illustrates a top view of a heat dissipation module with a topcover of the centrifugal fan removed according to a second embodiment ofthis invention. FIG. 4 illustrates a top view of a heat dissipationmodule with a top cover of the centrifugal fan removed according to athird embodiment of this invention. More searches have been conducted onthe reverse flow issue for other types of centrifugal fans. The windstop section varies within a range. In FIG. 3, a narrower wind stopsection 112 a′ is a wind-stop sponge or other wind-stop materialscontained within the heat dissipation fin array 112. The wind stopsection 112 a′ is about 0.1 L in length, which begins 0.56 L from thefirst sidewall 102 c and ends 0.66 L from the first sidewall 102 c. InFIG. 4, a wider wind stop section 112 a″ is a wind-stop sponge or otherwind-stop materials contained within the heat dissipation fin array 112.The wind stop section 112 a″ is about 0.42 L in length, which begins 0.4L from the first sidewall 102 c and ends 0.82 L from the first sidewall102 c. In sum, the wind stop section may have a length ranging fromabout 0.1 L to about 0.42 L.

FIG. 5 illustrates a top view of a heat dissipation module with a topcover of the centrifugal fan removed according to a fourth embodiment ofthis invention. FIG. 6 illustrates a top view of a heat dissipationmodule with a top cover of the centrifugal fan removed according to afifth embodiment of this invention. In the first, second and thirdembodiments, the wind-stop section is contained within the heatdissipation fin array 112. In the fourth embodiment of FIG. 5, the windstop section 112 b is a wind-stop tape attached to a side of the heatdissipation fin array 112 which faces the radial air outlet 102 a of thecentrifugal fan 102. In the fifth embodiment of FIG. 6, the wind stopsection 112 c is a wind-stop tape attached to a side of the heatdissipation fin array which faces away from the radial air outlet 102 aof the centrifugal fan 102.

With the wind stop section of the heat dissipation fin array, thereverse flow issue can be resolved so as to deal with the hot spot issueon the heat dissipation module as well as the temperature over-spec. onthe bottom cover of the notebook computer.

According to the above-discussed embodiments, the heat dissipationmodule disclosed herein employs its wind-stop section on the heatdissipation fin array to deal with the reverse flow issue at the radialair outlet of the centrifugal fan, thereby resolving the hot spot issueon the heat dissipation module as well as the temperature over-spec. onthe bottom cover of the notebook computer.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. A heat dissipation module comprising: acentrifugal fan comprising at least one axial air inlet and a radial airoutlet, wherein the radial air outlet is defined between a firstsidewall and an opposite second sidewall with a tongue potion; and aheat dissipation fin array disposed at the radial air outlet of thecentrifugal fan, wherein the heat dissipation fin array and the radialair outlet substantially share an equal length L, the heat dissipationfin array has a middle wind stop section which is closer to the secondsidewall than the first sidewall, the wind stop section has a lengthranging from about 0.1 L to about 0.42 L.
 2. The heat dissipation moduleof claim 1, wherein the length of the wind stop section is about 0.26 L.3. The heat dissipation module of claim 2, wherein the wind stop sectionbegins 0.48 L from the first sidewall and ends 0.74 L from the firstsidewall.
 4. The heat dissipation module of claim 1 further comprising aheat pipe which has a first end connected with the heat dissipation finarray and a second opposite end connected with a heat source.
 5. Theheat dissipation module of claim 1, wherein the wind stop section is awind-stop sponge contained within the heat dissipation fin array.
 6. Theheat dissipation module of claim 1, wherein the wind stop section is awind-stop tape disposed at a side of the heat dissipation fin arraywhich faces the radial air outlet.
 7. The heat dissipation module ofclaim 1, wherein the wind stop section is a wind-stop tape disposed at aside of the heat dissipation fin array which faces away from the radialair outlet.
 8. The heat dissipation module of claim 1, wherein thelength of the wind stop section is about 0.1 L.
 9. The heat dissipationmodule of claim 8, wherein the wind stop section begins 0.56 L from thefirst sidewall and ends 0.66 L from the first sidewall.
 10. The heatdissipation module of claim 1, wherein the length of the wind stopsection is about 0.42 L.
 11. The heat dissipation module of claim 10,wherein the wind stop section begins 0.4 L from the first sidewall andends 0.82 L from the first sidewall.
 12. The heat dissipation module ofclaim 1, wherein the centrifugal fan comprises an impeller with multipleblades, and each blade has a free end curved forward in a rotationdirection of the impeller.